I am usually into slower dubstep like plastician, dfrnt, and scuba, but the best stuff for the dance tent would be some bouncy mainstream dubstep like rusko's woot boost or skream's midnight request line.
I feel like dubstep might be to much for most people so bassnecter would be a good happy medium.( I don't really like him myself though.)
dubstep is not popular?? where do you live? if they can book hudmo.. they can book flying lotus, joker, kode9, ramadanman, mount kimbie, etc.
hopefully they stay away from rusko & the wobblers.. but that's likely the type that would get a set later in the night. book some house djs like omar s, masters at work, karizma, theo parrish, etc. but that won't happen